Adsorbent cartridge assembly with end cap

ABSTRACT

This invention relates to an adsorbent cartridge assembly having at least one end cap, and systems related thereto, for removing gaseous contaminants from the air or other gases.

This application claims the benefit of priority of U.S. ProvisionalAppl. 61/393,273, filed Oct. 14, 2010, which is incorporated herein byreference in its entirety.

TECHNICAL FIELD

This invention relates to an adsorbent cartridge assembly having atleast one end cap, and systems related thereto, for removing gaseouscontaminants from the air or other gases.

BACKGROUND

A carbon dioxide removal system maintains carbon dioxide (CO₂)concentration at a safe level. Maintaining CO₂ at safe levels can beaccomplished by passing exhaled or inhaled gases through a canisterfilled with a chemical adsorbent, such as soda lime or anhydrous lithiumhydroxide (LiOH). Several manufacturers make these adsorbents and usetheir own special mixes. For example, SODASORB®, manufactured by W. R.Grace & Co., is composed of a mixture of sodium hydroxide, calciumhydroxide, and potassium hydroxide.

Adsorbents are typically in the form of small granules that aregenerally sized between 0.04 to 0.25 inches (1.0 to 6.5 mm; 1 to 18mesh) in diameter. The granules may be poured directly into a canisterfor scrubbing CO₂. The gas to be scrubbed is forced through the granuleseither by lung power or by fan supplied power. Due to the generation ofairborne caustic dust, the handling or pouring of granules in confinedspaces is an undesirable operation.

Pre-filled granular cartridges offer the ease of use characteristicsover loose granules, but these pre-filled canisters still have issueswith shipping and handling or in-use shock and vibration, which causeschemical dusting of the adsorbent, settling of adsorbent which changespressure drop, channeling of gases around the adsorbent (along the outerwall), all of which result in variable adsorbent performance. Pre-filledcartridges are installed into a canister/outer housing for use withinequipment for scrubbing of CO_(2.)

An alternative to granular adsorbent is the ExtendAir® adsorbentcartridge (Micropore Inc.). This technology as generally described inU.S. Pat. No. 5,964,221 solves all of the aforementioned issues whichgranular adsorbents have, while also providing the ease of usecharacteristics desired.

For many applications, an ExtendAir® adsorbent sheet is wound on acylindrical core, but is sometimes stacked to form a cube or othershapes. The adsorbent is prevented from unwinding or losing shape byusing an inexpensive polymer film wrapped around the exterior of thecartridge. This cartridge has ease of handling advantages offered by thepre-filled granular canisters and reduces or eliminates dusting, withoutthe added manufacturing cost and bulk, of a completely enclosing plasticor metal housing.

However, the ends of the adsorbent cartridge assembly may become damagedduring shipping, handling or even in-use. Further, the size or shape ofthe cartridge may not allow use of the cartridge with canisters ofdifferent shapes or sizes than that of the cartridge. In addition, forcertain applications, the adsorbent material of the cartridge may beincompatible with direct contact with the canister material. Finally, itis desirable to produce an assembly that enables a uniform end seal orperimeter seal surface, without blocking perimeter flow channels. In thecase of a cylindrical adsorbent cartridge, the seal would have toaccommodate the step in the spirally wound cartridge, resulting from theoutermost layer of the adsorbent sheet material.

Hence, there is a need for improved adsorbent cartridges to meet theseneeds. This invention addresses these needs and others.

SUMMARY

The present invention provides, inter alia, an adsorbent cartridgeassembly for removing gaseous contaminants, comprising:

(a) one or more adsorbent surfaces arranged in multiple layers withedges of the layers forming two open end faces of a three-dimensionalcartridge, wherein the open end faces are at opposite ends of thecartridge; and wherein the layers are mechanically spaced to allow gasflow between the layers from one open end face of the cartridge to theother open end face of the cartridge;

(b) an end cap extending about and covering at least portions of anouter surface of the cartridge adjacent to one open end face of thecartridge.

In some embodiments, the end cap protrudes beyond the cartridge so as toextend beyond the outer portion of the cartridge in a direction of flowthrough the assembly, the end cap having an inner surface.

The present invention further provides an adsorbent cartridge assemblyfor removing gaseous contaminants, comprising:

(a) an adsorbent cartridge, comprising one or more adsorbent surfacesarranged in multiple layers, wherein said surfaces arranged in multiplelayers comprise a first open end face, a second open end face, and anouter portion; wherein:

the open end faces are at opposite ends of the cartridge;

said layers are disposed orthogonally with respect to the open endfaces; and

said layers are mechanically spaced so as to allow gas flow between saidlayers; and

(b) an end cap secured around said first open end face, comprising:

an outer sleeve circumscribing the outer portion of one end of thecartridge adjacent to said first open face; wherein said outer sleevehas a portion protruding beyond said one end of the cartridge; and theprotruding portion comprises an inner surface.

In some embodiments, the end cap further comprises an inner sleeveinserted into the inner core of the roll; and a plurality of radial ribsarranged substantially equidistant from each other connecting the innersleeve to the inner surface of the protruding portion of the outersleeve.

In some embodiments, the end cap further comprises a sealing ring moldedto the inner surface of the protruding portion of the outer sleeve, thesealing ring surrounding the entire inner circumference of the outersleeve.

In some embodiments, the sealing ring is co-molded to the inner surfaceand is of a different material than the remainder of the end cap.

In some embodiments:

the cartridge comprises one adsorbent surface wound into a roll to formthe multiple layers mechanically spaced by ribs disposed on theadsorbent surfaces; wherein the roll has an inner core, parallel to gasflow and perpendicular to the open end faces, said inner core beingcoaxial to the outer portion of the roll;

the end cap further comprises an inner sleeve inserted into the innercore of the roll; and a plurality of radial ribs arranged substantiallyequidistant from each other connecting the inner sleeve to the innersurface of the protruding portion of the outer sleeve;

wherein the end cap further comprises a sealing ring co-molded to theinner surface of the protruding portion of the outer sleeve, the sealingring surrounding the entire inner circumference of the outer sleeve,wherein the sealing ring is of a different material than the remainderof the end cap.

This invention offers the advantages of providing a uniform end seal orperimeter seal surface, without blocking perimeter flow channels. Theperimeter seal is possible with the end cap even though there is a stepin the spirally wound cartridge. The sealing surface can be made morerigid than one might choose if sealing directly to the adsorbentcartridge surface, separating superior adsorbent material properties,from superior sealing material properties. The end cap can protect theends of the adsorbent cartridge from damage during shipping, handling oreven in-use. Further, use of an end cap which is chemically compatiblewith caustics with a cartridge that eliminates chemical dusting canallow for the canister to be made of materials that may not becompatible with the adsorbent chosen. The cartridge assembly allows fulluse of the adsorbent (flow through outer channels), while allowing theoutlet of the cartridge assembly to be a different shape or size to thatof the adsorbent cartridge (e.g., to convert from a 6 inch to 5 inchdiameter, or vice versa; to convert from a cylindrical cartridge to asquare outlet or inlet, or vice versa).

The details of one or more embodiments of the invention are set forth inthe accompanying drawings and the description below. Other features,objects, and advantages of the invention will be apparent from thedescription and drawings, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1( a) is a three-quarter perspective view of an adsorptioncartridge of the present invention where the cartridge is cylindricaland the sheets are spiral.

FIG. 1( b) is a cross-section top view of the adsorption canister ofFIG. 1( a) where the sheets inside the canister have a spiralconfiguration.

FIG. 1( c) is an enlargement of the circular area of the cross-sectionshown in FIG. 1( b) showing the sheets separated by a separating means.

FIG. 1( d) is a cross-section view of an adsorption sheet of the presentinvention where the sheet is formed of expanded polytetrafluoroethylenewith adsorbent particles encapsulated within.

FIG. 1( e) is a cross-section view of an adsorption sheet of the presentinvention where the sheet of FIG. 1( d) is surrounded by an outermembrane.

FIG. 1( f) is a cross-section view of an adsorption sheet of the presentinvention where adsorbent material is attached to an internal screen andouter membranes are attached to the adsorbent particles.

FIG. 1( g) is a cross-section view of an adsorption sheet of the presentinvention where outer membranes are attached to an internal screen andthe interstices in the screen contain adsorbent material.

FIGS. 1( h) through 1(k) are three-quarter elevation views of a methodfor forming the sheet of FIG. 1( g).

FIG. 1( l) is a scanning electron micrograph (SEM), enlarged 5,000times, of a cross section of an adsorbent sheet of the present inventionwere the adsorbent powder is formed into a microporous sheet bythermally induced phase separation of polyethylene.

FIG. 1( m) is a three-quarter top elevation view of an adsorbent sheetfor use in the present invention, in which separating ribs have beenmolded on one side of the sheet out of the adsorbent itself.

FIG. 1( n) is a cross-section view of the adsorbent sheet shown in FIG.1( m).

FIG. 1( o) is a three-quarter top elevation view of another embodimentof an adsorbent sheet for use in the present invention, in whichseparating ribs have been molded in an angular fashion on one side ofthe adsorbent sheet.

FIG. 1( p) is a three-quarter side elevation view of still anotherembodiment of an adsorbent sheet for use in the present invention, inwhich separating ribs have been molded in an angular fashion on bothsides of the adsorbent sheet.

FIG. 1( q) is a detailed view of the adsorbent sheet illustrated in FIG.1( p).

FIG. 2( a) is an embodiment of an adsorbent cartridge assembly with endcaps.

FIG. 2( b) shows a plastic sleeve wrapped around an adsorbent cartridgeassembly.

FIG. 2( c) shows a flow cone attached to an end cap.

FIG. 2( d) shows an embodiment of an end cap with two opposing coreplugs arranged so that two or more cartridges can be stacked togetherusing the end cap.

FIG. 3( a) shows an embodiment of the adsorbent cartridge assembly witha cap.

FIG. 3( b) shows a cross-sectional view of the cartridge assembly shownin FIG. 2( a).

FIG. 4( a) shows an embodiment of the cartridge assembly using two flowcones which are snapped on to the end caps of the cartridge. A thin filmshrink wraps around the cartridge and end caps to secure the wholeassembly.

FIG. 4( b) shows a detailed view of the mechanism through which the flowcone of FIG. 3( a) is attached onto the end cap.

FIG. 5( a) shows another embodiment of the cartridge assembly with anend cap.

FIG. 5( b) shows a detailed view of an end cap having a ledge around itsinner protruding side.

FIG. 6( a) shows an adsorbent cartridge assembly with an end cap thatfurther includes a flow cone.

FIG. 6( b) shows an end cap with a circumscribed groove on its outersleeve.

FIG. 7 shows an embodiment in which air flow is directed to exit acartridge assembly through the same open end face from which the airflow entered, by the use of a dome shaped end cap.

FIG. 8 shows a cross-section of an embodiment of the assembly as across-section, whereby an end cap being held by shrink wrap in additionto various sizes using different number of ribs (spokes) and inclusiveof an integral core plug.

FIG. 9 shows an embodiment whereby the canister body is sealed to theflow cone 111 by O-ring 801, and the flow cone 111 is sealed to the endcap 803 by O-ring 802.

FIG. 10 shows an embodiment whereby the flow cone 901 is sealed to theend cap 902 by O-ring 903. Noting the flow cone is sealed to thecanister body in another location.

FIG. 11-13 show another embodiment of the adsorbent cartridge assemblywith an end cap and a flow cone.

FIG. 14 shows two embodiments of end caps having different geometryallowing for different methods of grip on the cartridge which mayeliminate the need for an outer wrap to secure the end cap to thecartridge.

FIG. 15 shows an embodiment of a cartridge assembly.

FIG. 16 shows a co-molded end cap with a sealing ring.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

The present invention provides, inter alia, an adsorbent cartridgeassembly that is designed to provide efficient adsorption, mechanicalresistance to the adsorbent cartridge against shocks and vibrations,help reduce or eliminate air by-passing the cartridge, and preventdamages due to caustic reaction between the cartridge and inner walls ofa canister. As the mechanism for removing gaseous contaminants from agas is dependent on the particular material chosen, the use of the word“adsorption” in this specification is meant to include adsorption,absorption, chemisorption, physisorption, catalysis etc.

Accordingly, disclosed herein, inter alia, is an adsorbent cartridgeassembly for removing gaseous contaminants, comprising:

(a) one or more adsorbent surfaces arranged in multiple layers withedges of the layers forming two open end faces of a three-dimensionalcartridge, wherein the open end faces are at opposite ends of thecartridge; and wherein the layers are mechanically spaced to allow gasflow between the layers from one open end face of the cartridge to theother open end face of the cartridge;

(b) an end cap extending about and covering at least portions of anouter surface of the cartridge adjacent to one open end face of thecartridge.

In some embodiments, the end cap protrudes beyond the cartridge so as toextend beyond the outer portion of the cartridge in a direction of flowthrough the assembly, the end cap having an inner surface. In someembodiments, the outer surface of the end cap may be of largerdimensions than the outer surface of the cartridge. In some embodiments,the outer surface of the end cap may be of different shape than theouter surface of the cartridge.

In some embodiments, the present invention provides an adsorbentcartridge assembly comprising:

(a) an adsorbent cartridge, comprising one or more adsorbent surfacesarranged in multiple layers, wherein said surfaces arranged in multiplelayers comprise a first open end face, a second open end face, and anouter portion; wherein:

the open end faces are at opposite ends of the cartridge;

said layers are disposed orthogonally with respect to the open endfaces; and

said layers are mechanically spaced so as to allow gas flow between saidlayers; and

(b) an end cap secured around said first open end face, comprising:

an outer sleeve circumscribing the outer portion of one end of thecartridge adjacent to said first open face; wherein said outer sleevehas a portion protruding beyond said one end of the cartridge; and theprotruding portion comprises an inner surface.

In some embodiments, the outer sleeve further comprises one or moresupporting members extending from the inner surface of the protrudingportion of the outer sleeve and protruding at least partially over thefirst open end face.

In some embodiments, the one or more supporting members is a singlemember circumscribing the inner surface of the protruding portion of theouter sleeve.

In some embodiments:

the end cap further comprises an inner hub aligned over the center ofsaid first open end face; and

the one or more supporting members comprise a plurality of radial ribsconnecting the inner hub to the inner surface of the protruding portionof the outer sleeve.

In some embodiments, the plurality of radial ribs are arrangedsubstantially equidistant from each other.

In some embodiments, the inner hub is a disc.

In some embodiments, the inner hub is a ring.

In some embodiments, the cartridge comprises one adsorbent surface woundinto a roll to form the multiple layers; wherein said roll has an outerportion.

In some embodiments, the roll has an inner core, parallel to gas flowand perpendicular to the open end faces; wherein said inner core iscoaxial to the outer portion of the roll.

In some embodiments, the inner core is solid.

In some embodiments, the inner core is hollow.

In some embodiments:

-   -   the end cap further comprises a hub centered over the inner        core; and    -   the one or more supporting members comprise a plurality of        radial ribs connecting the inner hub to the inner surface of the        protruding portion of the outer sleeve.

In some embodiments:

the hub comprises a ring arranged concentrically to the outer sleeve;and

the one or more supporting members comprise a plurality of radial ribsconnecting the inner ring to the inner surface of the protruding portionof the outer sleeve.

In some embodiments, the assembly further comprises a plug inserted intothe ring.

In some embodiments, the assembly further comprises core plugs insertedinto the ring in opposing directions so as to connect more than onecartridge in series.

In some embodiments:

the hub comprises a disc arranged concentrically to the outer sleeve;and

the one or more supporting members comprise a plurality of radial ribsconnecting the inner ring to the inner surface of the protruding portionof the outer sleeve.

In some embodiments:

the inner core is hollow;

the inner hub comprises an inner sleeve inserted into the inner core;and

the one or more supporting members comprise a plurality of radial ribsconnecting the inner sleeve to the inner surface of the protrudingportion of the outer sleeve.

In some embodiments:

the inner core is hollow;

the inner hub comprises a plug inserted into the inner core; and

the one or more supporting members comprise a plurality of radial ribsconnecting the plug to the inner surface of the protruding portion ofthe outer sleeve.

In some embodiments, the hub has substantially the same dimension as theinner core of the roll.

In some embodiments, the cartridge further comprises a foam or sealingmaterial covering at least a portion of an outer layer of the roll.

In some embodiments, the cartridge further comprises a foam or sealingmaterial inserted under an outer layer of the roll.

In some embodiments, the layers are spaced by ribs disposed on theadsorbent surfaces.

In some embodiments, the layers are spaced by separating screens betweenthe adsorbent surfaces.

In some embodiments, the end cap is secured to said first open end faceby any method chosen from the group of: ultrasonic welding,shrink-wrapping, adhesives, and molding.

In some embodiments, the end cap is secured to the first open end faceby a shrink wrap covering the outer portion of the cartridge and atleast a portion of the outer sleeve.

In some embodiments, the outer sleeve tapers in the direction of theprotruding portion allowing the end cap to be secured to the cartridgewithout any external securer.

In some embodiments, the outer sleeve further comprises a groovecircumscribing the outer portion of the outer sleeve.

In some embodiments, the end cap is secured to said first open end faceby a shrink wrap covering the outer portion of said cartridge andextending into the groove.

In some embodiments, the assembly further comprises a cone securedaround the outer sleeve, wherein said cone comprises an opening with asmaller diameter than the first open end face.

In some embodiments, the outer sleeve further comprises a groovecircumscribing the inner surface of the protruding portion of the outersleeve; and the cone further comprises a protrusion on an outer surfaceof the cone, which locks into the groove.

In some embodiments, the assembly further comprises a sealant disposedbetween the cone and the inner surface of the protruding portion of theouter sleeve.

In some embodiments, the sealant is an o-ring.

In some embodiments, the inner core is hollow; and wherein said assemblyfurther comprises a dome secured around the outer sleeve.

In some embodiments, the end cap is made from materials capable ofabsorbing shocks and/or contains flexible material suitable for makingsealing attachment of the end cap to the cartridge.

In some embodiments, the cartridge has more than one axially extendedchannel within its interior through which gas can flow.

In some embodiments, the end cap further comprises means to promote auniform flow of air across a cross-sectional surface of the cartridge.In some embodiments, means is selected from the group of a flowdeflector plate, a filter, a ring with sloping ribs and a disc.

In some embodiments, the assembly further comprises a second end capsecured around the second open end face, comprising:

an outer sleeve circumscribing the outer portion of an end of thecartridge adjacent to said second open face; wherein said outer sleevehas a portion protruding beyond the end of the cartridge adjacent tosaid second open face; and the protruding portion comprises an innersurface.

In some embodiments, the present invention provides a gaseouscontaminant removal system, comprising:

-   -   (a) the assembly of any one of one of the aforementioned        embodiments, or combination thereof; and    -   (b) a canister for housing said cartridge;

wherein:

said canister comprises an inlet through which gas can flow to contactthe adsorbent cartridge; and an outlet for gas flow; wherein one of theopen end faces of the cartridge is adjacent to the inlet.

In some embodiments, the second open end face is adjacent to the inlet.

In some embodiments, the assembly further comprises a sealant disposedbetween the inner wall of the canister and the protruding portion of theouter sleeve, so that air is directed into and does not by-pass thecartridge.

In some embodiments, the term “open end faces are at opposite ends ofthe cartridge” means one open end provides an inlet for gas flow and theother open end provides for outlet for gas flow through the cartridge.In some embodiments, the open end faces are parallel to each other atopposite ends of the cartridge. In some embodiments, the open end facesare not parallel to each other, wherein the cartridge has curvature.

In general, the adsorbent cartridges of the invention do not require arigid outer housing. The adsorbent cartridge has the advantage ofinstead using a less expensive end cap to interconnect the cartridge tothe inlet and/or outlet of the gas system (e.g., the canister).Preferably, this allows the end cap to interconnect the cartridge to thegas system (e.g., canister) without need of fastening to the inletand/or outlet of the gas system (e.g., without need of adhesive ormechanical fasteners between the cartridge and the canister inlet oroutlet).

The cartridge and end cap are described in more detail below.

Adsorbent Cartridge

The cartridges include, but are not limited to, ExtendAir® cartridgesand those described in U.S. Pat. No. 7,329,307, U.S. Pat. No. 7,326,280,and U.S. Pat. No. 5,964,221, each of which is incorporated herein byreference in its entirety.

The adsorbent cartridge includes adsorbent surfaces that are arranged inmultiple layers. Generally, the surfaces are mechanically spaced (e.g.,by ribs or other spacers, screens, etc.) where the spacers are incontact with the next adjacent sheet. In some embodiments, the spacersare parallel to the direction of air flow. In some embodiments, thesheets may be flat, or pleated, or contain ribs therein.

In some embodiments, the sheets are wound into a cylinder but thecartridge may also be of other geometries. In the wound embodiments, thesheet 30 is spiraled (i.e., arranged in a continuous helix or asseparate rings or helixes arranged concentrically) as shown asillustrated in FIG. 1( a). Air flow through the cartridge can be fromboth directions (top to bottom, or bottom to top) and is parallel to thespiraled adsorbent sheet surfaces. FIG. 1( b) shows a top view ofcylindrical cartridge 20 of FIG. 1( a) with adsorbent sheet 30 arrangedin a “spiral” configuration where the sheet is wrapped around thecenter. FIG. 1( c) shows separating screens 32 positioned between thespirally positioned sheets 30.

In some embodiments, the sheets are stacked into a cube or rectangularshape (90 degree corners on all sides but length, width and depth may ormay not be identical). In some embodiments, the adsorbent surfaces areplanar. The term “planar” used to describe surfaces means that theadsorbent surfaces are substantially without curvature (e.g., thesurfaces are not rolled). A sealing material (foam or rigid) may be usedto seal two or more sides of the cube or rectangle, leaving two open endfaces (to allow for air flow), two outer surfaces formed by theadsorbent sheets, and two foam surfaces.

In some embodiments, each adsorbent surface comprises the same type ofadsorbent. In other embodiments, each adsorbent surface is independentlyselected from various adsorbents.

The Manufacture of Adsorbent Surfaces

In some embodiments, the gaseous contaminant is carbon dioxide. In someembodiments, the adsorbent material used in the adsorbent surfaces iscalcium hydroxide or lithium hydroxide.

Further description of LiOH adsorbent sheets can be found in, forexample, Hrycak et al. in U.S. Pat. No. 7,329,307 and U.S. Pat. No.7,326,280, each of which is incorporated herein by reference in itsentirety. Further description of Ca(OH)₂ adsorbent sheets and othertypes of adsorbent sheets can be found in, for example, in McKenna, U.S.Pat. No. 5,964,221, which is incorporated herein by reference in itsentirety.

In one embodiment shown in FIG. 1( d), sheet 30 is formed of anadsorbent filled expanded porous PTFE sheet having a microstructure ofnodes 40 interconnected with fibrils 41 wherein adsorbent material 39 ispresent in the voids of the PTFE structure as taught by U.S. Pat. No.4,985,296 issued to Mortimer, Jr., incorporated herein by reference inits entirety. This sheet is water repellent, but air-permeable. Ideally,particles 39 are packed in a multi-modal (e.g., bi-modal or tri-modal)manner, with particles of different sizes interspersed around oneanother to fill as much of the available void space between particles asis possible so as to maximize the amount of active material contained inthe sheet. This technique also allows more than one type of adsorbentparticle to be filled into a single sheet.

By using filled porous expanded polytetrafluoroethylene (PTFE) as sheet30, a number of additional advantages are further imparted. ExpandedPTFE is a non-linting, non-out-gassing inert material that effectivelyreduces dusting of adsorbent material during manufacturing and duringthe life of the filter. Additionally, processing advantages of thismaterial include the ability to make a relatively thin material that canbe produced in a wide sheet and then cut (or cut and pleated) intodesired configurations.

The properties of CO₂ adsorbent filled PTFE sheet are such that no othersupporting fabric or material is needed to maintain structuralintegrity. In fact, not only can this filled PTFE sheet withstandflexing, pleating and mechanical vibration under dry conditions, thehydrophobicity of the PTFE offers this structural durability even whilesubjected to direct liquid water contact. Another embodiment of sheet 30is shown in FIG. 1( e), where filled PTFE sheet 30 is encapsulatedbetween two hydrophobic gas-permeable membranes 42. These outermembranes 42 add extra protection to ensure that adsorption material 40is contained within sheet 30 while preventing water from reaching theadsorbent contained in the sheet. Membranes 42 must have a high degreeof filtration efficiency to prevent adsorbent particles from escapinginto the breathing atmosphere. These membranes 42 preferably compriseporous expanded polytetrafluoroethylene (PTFE), because it ishydrophobic and offers high particulate filtration efficiency.

A third embodiment of the sheet is shown in cut-away FIG. 1( f) where aninternal screen 43 is encapsulated by adsorbent material 39 that issurrounded by two hydrophobic gas-permeable membranes 42.

A fourth embodiment of the sheet 30 is shown in FIG. 1( g) where aninternal screen 44 is attached to two hydrophobic gas-permeablemembranes 42 and adsorbent material 39 is positioned in the voidsbetween screen members 44.

FIGS. 1( h) thorough 1(k) illustrate a method for making sheet 30 ofFIG. 1( g) having an internal screen 44, adsorbent material 39, andouter membranes 42. FIG. 1( h) depicts internal screen 44. Next, in FIG.1( i), internal screen 44 is attached to a membrane 42 by a laminationprocess. Subsequently, in FIG. 1( j), adsorbent material 39 is addedinto the open cells of internal screen 44. Afterwards, in FIG. 1( k), asecond membrane 42 is laminated to the top of the internal screen 44,thereby encapsulating adsorbent material 40 within.

FIG. 1( l) is a scanning electron micrograph of another embodiment ofsheet 30 used in the cartridges described herein. This structure isproduced by way of thermally induced phase separation, such as in thefollowing manner.

A water repellent polymer, such as ultra high molecular weightpolyethylene, is combined with a gas adsorbent material, such as calciumhydroxide powder. This combination may be accomplished by combining thetwo materials together in an extruder. By conveying this mixture throughthe extruder and mixing with a lubricant, such as mineral oil, thepolymer dissolves in the lubricant and become uniformly mixed with theadsorbent and lubricant. This mixture can then be extruded into acomposite sheet or other shape.

The composite sheet may be calendared to further flatten the sheet ifdesired. The lubricant may then be extracted out of the resulting sheetusing a solvent, such as hexane. The solvent may then be removed, suchas through use of a dry nitrogen purge.

The resulting structure is highly micro-porous, allowing for thediffusion of CO₂ or other gases, and yet is able to be produced withvery high adsorbent powder loadings per unit volume. Additionally, if avery strong polymer, such as Ultra High Molecular Weight Polyethylene isused, a very small amount of polymer is required to make the sheetstructurally stable, which allows for even higher adsorbent loadings perunit volume. While typical powder loadings for this type ofmanufacturing process are on the order of 50 to 60% filler powder afterprocess oil extraction, loadings well above 60% may be possible. In someembodiments, adsorbent loading is greater or equal to about 90% byweight. In some embodiments, adsorbent loading is greater or equal toabout 97%. Additionally, in some embodiments, the material is moldedinto any desired shape, and thus, the separating means may beaccomplished by molding separating ribs onto the surface of the sheet.

Various embodiments of this molded structure are illustrated in FIGS. 1(m) through 1(q). By molding the separating elements 33 (or “ribs”)directly out of adsorbent material, not only is the adsorbent cartridgeeasier to produce, but, because of its self-separating properties, thetotal amount of adsorbent in the filter can be increased by 10 to 30percent.

End Cap

The use of a uniform end cap to which an adsorbent cartridge can seal,helps to overcome problems associated with 1) air by-pass due tophysical gaps between the cartridge and the housing canister, 2) damagedue to caustic reaction between the cartridge and the inner walls of thehousing canister, and 3) mechanical fragility of unprotected cartridges.An example of an adsorbent suitable for medical applications is theEclipse™ CO₂ Adsorbent, which includes end caps.

FIGS. 2( a) and 2(b) show embodiments of an assembled cartridge 100, awound adsorbent cartridge 101 with foam 102 either covering the end ofthe cartridge or wound partially under the last wrap of adsorbentmaterials. The actual size and position of foam 102 can be tailored tospecific applications. Foam 102 aids in preventing airflow fromby-passing the cartridge. An end cap 103 can then be attached on one ormore open end faces of the cartridge. Surfaces of the adsorbentmaterials are arranged in multiple layers 116 in cartridge 101. Firstopen end face 104 is parallel to second open end face 115, both endfaces are at opposite ends of the cartridge. Besides the two open endfaces, cartridge 101 also includes an outer portion 121. Multiple layers116 are arranged orthogonally with respect to both open end faces.Multiple layers 116 are mechanically spaced from one another such thatgas flow between the layers is not obstructed. In some embodiments, themechanical spacing is provided by ribs 33 as shown in FIG. 1( m). Endcap 103 includes an outer sleeve 107, which forms a protruding portion117 when end cap 103 is secured around open end face 104 of cartridge101. Protruding portion 117 also includes an inner surface 118, thesefeatures are more clearly illustrated in FIG. 3( b). In someembodiments, end cap 103 contains supporting members in the form ofradial ribs 109 that support an inner hub 108 through which a core plug106 can be engaged. Wound cartridge 101 has an inner core 105 into whichcore plug 106 can be inserted. Core plug 106 can be incorporated both asan integrated core plug and end cap assembly 120 or it may be part of anassembly formed in a unitary fashion.

Plastic, rubber and co-molded materials (e.g. plastic/rubber) can beused to fabricate end caps. Material choices are determined based on theintended applications of the end caps and are not limited to thematerials listed above. The actual manufacturing method used to producethe end cap can also vary. Manufacturing based on molded parts may besuitable for certain embodiments and applications. The adoptedmanufacturing method is based on the applications and constraintsimposed by the choice of material.

End cap 103 can be partially or completely formed from flexiblematerials that are able to seal elastically to cartridges, evencartridges with variability in their diameters. Sealing can be doneindependently of the cartridge diameter by inserting core plug 106 onend cap 103 into inner core 105 of wound cartridge 101. In general, endcap 103 is designed to be placed onto one end of cartridge such that theend cap makes a snug fit to the outer rim or perimeter of the cartridge.In this manner, the foam materials surrounding the cartridge can also besecured. Correct positioning of the end cap can be ensured through thecontact of radial ribs 109 with open end face 104 of the cartridge orthrough a fitting notch incorporated in the end cap profile. Ribs 109can also ensure protection against telescoping of cartridge material.

A polymer (e.g. plastic) film 110 can be applied to seal assembly 100around the outer surface of the cartridge, including the perimetersurfaces of the end caps, as shown in FIG. 2( b). For certainapplications, polymer film 110 can be heat sealed to the assembly. Insome embodiments, polymer film 110 extends over the outer edges of eachend cap when the assembly is wrapped. In some embodiments, end cap 103has a groove 520 (shown in FIG. 6( b) around the outer perimeter alongthe rim of end cap 103 to facilitate in securing film 110. Sealingmaterials do not fully encase end caps so that airflow through open endfaces 104 and 115 of cartridge is not obstructed.

Besides its use in sealing the outer surface of the cartridges, polymerfilm 110 also enables a cartridge to attach to an end cap such that thecartridges with variability in diameter can be accommodated within thecross-sectional surface of the end cap.

In some applications as shown in FIGS. 3( a) and 3(b), gas flow throughinner core 105 of cartridge 101 can be eliminated by the insertion ofcore plug 106 into the ends of inner core 105 after the cartridge andend caps are assembled. Besides eliminating gas flow, core plug 106 mayalso assists in securing the end caps. Based on the application, one orboth end caps can be designed to have a core plug that is eitherintegrated into the end cap or formed in a unitary fashion. Further asshown in FIG. 14, the design of the end cap may allow for instanceswhere the outer wrap is not required. For example, the protrudingportion of the end cap may taper (1401) and thereby eliminate the needfor a groove within end cap design. The length of the end cap can betailored to adjust the grip of the end cap to the cartridge. Inaddition, the outside ring can be angled in, or shaped in multiple waysto increase the grip on the cartridge, to thus eliminate the need for anouter shrink wrap.

In some applications as shown in FIG. 16, an end cap 1600 can beco-molded, in which a body 1601 of the end cap 1600 is fabricated fromone material and a seal section 1602 is made of another material. Thebody 1601 may include an outer sleeve 1603, radial ribs 1604 and aninner hub 1605. The sealing section 1602 may be disposed at one side ofan inner surface 1606 of the outer sleeve 1603 and surrounds the entirecircumstance of the one side of the inner surface 1606. The sealingsection 602 may protrude from outer sleeve 1603. In some applications,high density polyethylene (HDPE) may be used for the body 1061 of theend cap 1600 and a thermoplastic rubber (e.g., a crosslinked mixture ofpolypropylene and EPDM (ethylene-propylene-diene monomer) rubber, suchas Santoprene™) for the seal section 1602 of the end cap 1600. Othercombinations of materials for the body 1601 sealing section 1602 may beused, depending on the desired application.

Flow Cones

FIG. 2( c) shows a flow cone 111 with a tapered end 112 through whichpre-treated and treated gas can be directed into or out of the flow conerespectively. In some embodiments, the combination of flow cone 111 withend cap 103 can be used to connect breathing devices that have a smallerstandard tubing connection. Wider end 113 of flow cone 111 can be fittedonto (e.g. snapped on) end cap 103 to form assembly 114 shown in FIG. 2(c). In some embodiments, the flow cone and end cap assembly can bedesigned in an integrated fashion. The extended radial ribs in the endcap can help to direct gas flow to open end face 104 of the cartridge.Sealing is required between the end cap, the flow cone and the canisterhousing to eliminate gas flow that by-passes the cartridge.

A groove 520 (in FIG. 6 (b)) on the outer perimeter along the rim of endcap 103 allows a sealing film to be attached to the end cap. FIG. 6 (a)shows an example in which groove 520 can be used to allow the latchingof a flow cone 111 to the cartridge assembly. In some embodiments, thiscombination of flow cone 111 with end cap 103 can be used in cases wherea housing canister body is not required. Such applications may includeadsorbent systems that are designed for one time use.

One example in which a canister housing is not required is the REMO2®application, an embodiment of which is shown in FIG. 4( a). In theseapplications, the cartridge may not be perfectly sealed. Instead, a film301 is wrapped around the cartridge to help keep the tension in thewound cartridge and prevent gas entering from the sides of thecartridge. Two flow cones 302 are attached to open end faces ofcartridge 101. The structural requirements for the housing element insuch applications may be less stringent than those required in a typicalcanister. FIG. 4( b) shows the attachment mechanism of flow cone 302 toend cap 303.

The design of the flow cone can be tailored to specific applications. Insome embodiments, as shown in FIG. 10, flow cone 901 can be inserted tofit the inner diameter of the end cap 902. A single O-ring 903 fits intonotch 904 and is used to provide mechanical sealing to ensure air flowthrough the cartridge (and eliminating by-pass of the cartridge). Inembodiments, in which only a single O-ring is used, the end cap can beslipped more easily onto the O-ring.

Gas Flow Optimization

The embodiments described in this document can be modified in severalways to optimize gas flow through the adsorbent cartridge. In someembodiments, flow deflector plates can be inserted into end cap 103 toensure a good and even gas flow across the entire open end face 104 ofthe cartridge. In some embodiments, a screen (which can affect the flowrate and flow distribution) can be placed near the top of the end cap todeflect the gas flow and average the flow across the whole face of thecartridge. In some embodiments, the extended radial ribs may be slopedinstead of being arranged in a horizontal plane. These contoured ribsmay help to deflect the gas flow and even out the distribution of gasflow across the cartridge. In some embodiments, a flat disc is insertedin a portion of the end cap assembly to evenly distribute gas flow bymoving the gas stream to cover entire bounds of the cartridge.

Sealing Options Using O-Rings

In some embodiments, as shown from a cross-sectional view in FIG. 9, twoO-rings are used as sealants to seal an assembly featuring a cartridge,end cap, and flow cone installed in a housing canister. In theseembodiments, flow cone 111 is latched onto an end cap 803. A sealantO-ring 801 is used to seal and prevent the airflow from going around thecartridge such that by-pass of airflow can be minimized or eliminated. Asecond sealant O-ring 802 seals the end cap and the flow cone to ensurethat all airflow going through the flow cone passes through into thecartridge.

In some embodiments, the canister housing might already have sealingcapabilities, thus sealing may not be required at some or all perimetersurfaces between the flow cone and the end cap, and between the end capand the cartridge. In some embodiments, O-rings are used to form sealsbetween mating surfaces defined as the surfaces between the cartridgeand the top end of the lower end cap, and the surface between thecartridge and the lower end of the upper end cap. The necessity and useof seals for these surfaces are application specific.

In some embodiments, end caps may be attached to cartridges by means ofadhesives (e.g. glues) that are inert to both the adsorbent materialsand the gas flowing through the cartridge. The adhesives may be appliedaround the rim of a cartridge so that an end cap can be attached to thecartridge while not obstructing the flow of gas across open end face 104of the cartridge.

Different configurations of adsorbent systems require the use ofadsorbent cartridges having different sizes. These differently sizedcartridges in turn require end caps of different dimensions andconfigurations. In some embodiments, as shown in FIG. 5( a), end cap 401does not have extended radial ribs. Instead of having radial ribs assupporting members, end cap 401 has a ledge 119 around inner surface 118of protruding portion 117, as shown in FIG. 5( b).

In this configuration, a shrink wrap 403 made from, for example,polypropylene, polyolefin and polyethylene can be used to securecartridge 101 and ends caps 401 around the rims and outer surface of thecartridge and end caps. Plug 402 with a loop can be engaged directlyinto inner core 105 of cartridge 101, which can be used as a means topull the cartridge from the canister assembly.

Mechanical/Structural Protection of Cartridges

The integrated cartridge and end cap assembly is more robust againsthandling and shipping damages due to the shock absorbing capability andmechanical resistance afforded by the end caps. End caps may befabricated from flexible materials or combinations of rigid and flexiblematerials that are able to absorb shocks. Since cartridges are oftenpackaged in multiples with the cartridges arranged side by side, theability to absorb shocks and vibrations along a vertical dimensionacross which at least one end cap is secured is useful in reducingdamages on the cartridges incurred during shipment, without requiringthe use of more expensive packaging materials. With the additionalprotection provided by the end caps, simple packaging techniquesinvolving only standard metal foil composites bags placed inside astandard box could be utilized for shipping purposes. In addition, theend-user of the cartridges most commonly imparts vertical shocks andvibrations to the cartridge by subjecting the cartridges to verticaldrops when the cartridges are installed in a canister. End caps thushelp to ensure the integrity of cartridges both during shipment andinstallation of the cartridge by providing additional mechanicalresistance against shocks to the adsorbent cartridges.

In some embodiments, end caps can be designed to have a thicker sectionfor the rim and/or rib portions. Such a design would be more symmetric,which is more impact resistant and provides greater mechanical stabilityfor the cartridge assembly. FIG. 12 illustrates an example of an end cap1101 with thicker rim portion, which is engaged to a flow cone 1102.

Although end caps are generally used for wound cartridges, they can beused as means to reduce shipping and handling damages to non-cylindricalcartridges (e.g. square, rectangular, or oval) as well.

Inlet and Outlet of Airflow from the Same Face of a Cartridge

In some embodiments, particularly those in which the available physicalspace for the adsorbent system is limited, gas flow may be required toenter and exit the adsorbent cartridge from the same end face. Anexample of such an embodiment is illustrated in FIG. 7. End cap 601 isdomed-shaped and sealed on one end. Gas flows into the cartridge throughcore 105 of the cartridge. End cap 601 redirects the incoming gas in thereverse direction through the adsorbent cartridge such that theprocessed gas exits the same open end face 602 of the cartridge as theinflow of gas. End cap 601 is sealed to cartridge 603. End cap 601 maycontain additional features and components such as gas deflector plates,flow discs and filters to help channel and make the gas flow through thecartridge more uniform. In some embodiments, the gas flow is in thereverse direction, depending on the application.

In the embodiments shown in FIG. 2, cartridge 101 has one inner core105. In some embodiments, the cartridge may have more than one core. Theadditional cores can serve as channels through which gas may flow.

FIG. 8 shows both a top view and a cross sectional view of the adsorbentcartridge and endcap 701 with 3 spokes, the number of spokes will varybased on specific application and dimensions. The core plug 704 of theend cap is first used to engage the end cap to the cartridge beforewrapping film 703 is secured to the cartridge and end cap together.Wrapping film 703 shrinks to the outside perimeter of the cartridge andthe stepped face 702 provided on the end cap 701, in some applicationsthe end cap many have a tapered face to facilitate the attachment of thewrapping film.

In the embodiments shown in FIG. 13, end cap 1201 with a symmetricdesign is shown. Such a symmetric design of the end cap allowsambidextrous installation of the end-cap and cartridge assembly, at thesame time allowing a simpler mold design that may be advantageous in themanufacturing/production of these end caps.

In some embodiments, multiple cartridges are stacked. Each of themultiple cartridges can have its own housing canisters, or the differentcartridges can be joined by end cap 103 having two opposing core plugs106 as illustrated in FIG. 2( d) to connect the ends of differentcartridges. An exemplary application of these embodiments can be for anapplication in which airflow or other gases is first passed through acartridge containing molecular sieves to remove its moisture contentbefore the processed gas enters another cartridge arranged in series tohave carbon dioxide removed from it. Even though cartridges can be usedto treat gas flow entering the open end faces in both directions, whensymmetric end caps suitable for ambidextrous installation are used,safety features need to be in place to ensure that once installed, thedirection of airflow is clearly indicated. For example,cylindrical/circular cartridges are typically installed into taperedcanister housing in which the direction of airflow can be easilyidentified.

Example 1 Cartridge Assembly

The prototype cartridge assembly consists of a spirally wound cartridgeand a single end cap, both of which are cylindrical although aspreviously noted a wound cartridge will not be perfectly cylindrical dueto the step from the outer edge of the adsorbent sheet. The end cap inthe prototype is designed and manufactured with a number of spokes andan integral plug. When attaching the end cap to the cartridge theintegral plug slides into the central hollow core of the cartridge,which secures the end cap to the cartridge and also stops any flow ofgas through the hollow core when installed (e.g., in a breathingdevice). The end cap, attaches to the cartridge around its perimeter.The endcap is made of a rubber material and is designed to be of asmaller diameter than the cartridge, so that when installed the end capfits around the cartridge perimeter snugly. With this design, it has notbeen necessary to have an outer shrink wrap to hold the end-cap whenassembled. The chosen durometer of the prototype is 80 which allows forsome elasticity of the end cap to help when attaching to the cartridge.The rubber end cap also allows for a means to seal the cartridgeassembly in the canister and thus minimizes by-pass of the adsorbentmaterial. In some embodiments, the cartridge assembly is substantiallyas shown in FIG. 15.

A number of embodiments of the invention have been described.Nevertheless, it will be understood that various modifications may bemade without departing from the spirit and scope of the invention.Accordingly, other embodiments are within the scope of the followingclaims.

1-2. (canceled)
 3. An adsorbent cartridge assembly for removing gaseouscontaminants, comprising: (a) an adsorbent cartridge, comprising one ormore adsorbent surfaces arranged in multiple layers, wherein saidsurfaces arranged in multiple layers comprise a first open end face, asecond open end face, and an outer portion; wherein: the open end facesare at opposite ends of the cartridge; said layers are disposedorthogonally with respect to the open end faces; and said layers aremechanically spaced so as to allow gas flow between said layers; and (b)an end cap secured around said first open end face, comprising: an outersleeve circumscribing the outer portion of one end of the cartridgeadjacent to said first open face; wherein said outer sleeve has aportion protruding beyond said one end of the cartridge; and theprotruding portion comprises an inner surface.
 4. The assembly of claim3, wherein said outer sleeve further comprises one or more supportingmembers extending from the inner surface of the protruding portion ofthe outer sleeve and protruding at least partially over the first openend face.
 5. The assembly of claim 4, wherein the one or more supportingmembers is a single member circumscribing the inner surface of theprotruding portion of the outer sleeve.
 6. The assembly of claim 4,wherein: the end cap further comprises an inner hub aligned over thecenter of said first open end face; and the one or more supportingmembers comprise a plurality of radial ribs connecting the inner hub tothe inner surface of the protruding portion of the outer sleeve.
 7. Theassembly of claim 6, wherein said plurality of radial ribs are arrangedsubstantially equidistant from each other.
 8. The assembly of claim 6,wherein the inner hub is a disc.
 9. The assembly of claim 6, wherein theinner hub is a ring.
 10. The assembly of claim 3, wherein the cartridgecomprises one adsorbent surface wound into a roll to form the multiplelayers; wherein said roll has an outer portion.
 11. The assembly ofclaim 10, wherein the roll has an inner core, parallel to gas flow andperpendicular to the open end faces; wherein said inner core is coaxialto the outer portion of the roll.
 12. The assembly of claim 11, whereinthe inner core is solid.
 13. The assembly of claim 11, wherein the innercore is hollow.
 14. The assembly of claim 3, wherein: the end capfurther comprises a hub centered over the inner core; and the one ormore supporting members comprise a plurality of radial ribs connectingthe inner hub to the inner surface of the protruding portion of theouter sleeve.
 15. The assembly of claim 14, wherein: the hub comprises aring arranged concentrically to the outer sleeve; and the one or moresupporting members comprise a plurality of radial ribs connecting theinner ring to the inner surface of the protruding portion of the outersleeve.
 16. The assembly of claim 15, wherein the assembly furthercomprises a plug inserted into the ring.
 17. The assembly of claim 15,further comprising core plugs inserted into the ring in opposingdirections so as to connect more than one cartridge in series.
 18. Theassembly of claim 14, wherein: the hub comprises a disc arrangedconcentrically to the outer sleeve; and the one or more supportingmembers comprise a plurality of radial ribs connecting the inner ring tothe inner surface of the protruding portion of the outer sleeve.
 19. Theassembly of claim 14, wherein: the inner core is hollow; the inner hubcomprises an inner sleeve inserted into the inner core; and the one ormore supporting members comprise a plurality of radial ribs connectingthe inner sleeve to the inner surface of the protruding portion of theouter sleeve.
 20. The assembly of claim 14, wherein: the inner core ishollow; the inner hub comprises a plug inserted into the inner core; andthe one or more supporting members comprise a plurality of radial ribsconnecting the plug to the inner surface of the protruding portion ofthe outer sleeve.
 21. The assembly of claim 14, wherein the hub hassubstantially the same dimension as the inner core of the roll.
 22. Theassembly of claim 10, wherein the cartridge further comprises a foam orsealing material covering at least a portion of an outer layer of theroll.
 23. The assembly of claim 10, wherein the cartridge furthercomprises a foam or sealing material inserted under an outer layer ofthe roll.
 24. The assembly of claim 3, wherein the layers are spaced byribs disposed on the adsorbent surfaces.
 25. The assembly of claim 3,wherein the layers are spaced by separating screens between theadsorbent surfaces.
 26. The assembly of claim 3, wherein the end cap issecured to said first open end face by any method chosen from the groupof: ultrasonic welding, shrink-wrapping, adhesives, and molding.
 27. Theassembly of claim 3, wherein the end cap is secured to the first openend face by a shrink wrap covering the outer portion of the cartridgeand at least a portion of the outer sleeve.
 28. The assembly of claim 3,wherein the outer sleeve tapers in the direction of the protrudingportion allowing the end cap to be secured to the cartridge without anyexternal securer.
 29. The assembly of claim 3, wherein the outer sleevefurther comprises a groove circumscribing the outer portion of the outersleeve.
 30. The assembly of claim 29, wherein the end cap is secured tosaid first open end face by a shrink wrap covering the outer portion ofsaid cartridge and extending into the groove.
 31. The assembly of claim10, further comprising a cone secured around the outer sleeve, whereinsaid cone comprises an opening with a smaller diameter than the firstopen end face.
 32. The assembly of claim 31, wherein the outer sleevefurther comprises a groove circumscribing the inner surface of theprotruding portion of the outer sleeve; and the cone further comprises aprotrusion on an outer surface of the cone, which locks into the groove.33. The assembly of claim 31, further comprising a sealant disposedbetween the cone and the inner surface of the protruding portion of theouter sleeve.
 34. The assembly of claim 33, wherein the sealant is ano-ring.
 35. The assembly of claim 11, wherein the inner core is hollow;and wherein said assembly further comprises a dome secured around theouter sleeve.
 36. The assembly of claim 3, wherein the end cap is madefrom materials capable of absorbing shocks and/or contains flexiblematerial suitable for making sealing attachment of the end cap to thecartridge.
 37. The assembly of claim 3, wherein the cartridge has morethan one axially extended channel within its interior through which gascan flow.
 38. The assembly of claim 3, wherein the end cap furthercomprises means to promote a uniform flow of air across across-sectional surface of the cartridge.
 39. The assembly of claim 38,wherein the said means is selected from the group of a flow deflectorplate, a filter, a ring with sloping ribs and a disc.
 40. The assemblyof claim 3, wherein: the cartridge comprises one adsorbent surface woundinto a roll to form the multiple layers mechanically spaced by ribsdisposed on the adsorbent surfaces; wherein the roll has an inner core,parallel to gas flow and perpendicular to the open end faces, said innercore being coaxial to the outer portion of the roll; the end cap furthercomprises an inner sleeve inserted into the inner core of the roll; anda plurality of radial ribs arranged substantially equidistant from eachother connecting the inner sleeve to the inner surface of the protrudingportion of the outer sleeve; wherein the end cap further comprises asealing ring co-molded to the inner surface of the protruding portion ofthe outer sleeve, the sealing ring surrounding the entire innercircumference of the outer sleeve, wherein the sealing ring is of adifferent material than the remainder of the end cap.
 41. The assemblyof claim 40, wherein said sealing ring comprises a thermoplastic rubber;and the remainder of the end cap comprises a high density polyethylene.42. The assembly of claim 3, further comprising a second end cap securedaround the second open end face, comprising: an outer sleevecircumscribing the outer portion of an end of the cartridge adjacent tosaid second open face; wherein said outer sleeve has a portionprotruding beyond the end of the cartridge adjacent to said second openface; and the protruding portion comprises an inner surface.
 43. Agaseous contaminant removal system, comprising: (a) the assembly ofclaim 3; and (b) a canister for housing said cartridge; wherein: saidcanister comprises an inlet through which gas can flow to contact theadsorbent cartridge; and an outlet for gas flow; wherein one of the openend faces of the cartridge is adjacent to the inlet.
 44. The system ofclaim 43, wherein the second open end face is adjacent to the inlet. 45.The system of claim 43, further comprising a sealant disposed betweenthe inner wall of the canister and the protruding portion of the outersleeve, so that air is directed into and does not by-pass the cartridge.